Question

What is the coordination number of atoms in HCP structure?

Answer 1

Coordination number:

• The number of particles that surround a single particle in a crystal lattice is known as the coordination of that particle of the lattice.
• It also helps to measure the hardness of the crystal

HCP:

• HCP is a Hexagonal closed pack structure which is an example of $3$- dimensional packing.
• There are six spheres in one plane, 3 spheres above, and three spheres below the plane making it 12.
• Thus, each sphere is surrounded by 12 spheres which makes the coordination number of each particle 12.